86 C20 5.3/4l60e swap, MANY QUESTIONS!

[bloodybigblock]

So ive decided that posting many threads were annoying and took up room for anyone else with their own questions. I have a 86 c20 2wd with a 454/th400. I found a 01 DBC 5.3 with harness for a great deal. I have searched and searched hours and hours but all i can find is 67-72 info. I plan on having a CAI, electric fans,and a true dual exhaust since this wont be a hot rod.

1. What motor mounts? I'd like to run the stock manifolds and i want to keep my a/c.
2. I plan on lowering the truck, will my truck pan cause issues? Is there motor mounts that can raise the engine?
3. Best place to send my harness and ecm?
4. If i do my own harness, can it be driven to get the tune an hour from my house?
5. Any issues with running strait manifolds to make it to the muffler shop?


thats all the questions i have for now. Any help would be appreciated. Im ready to start buying parts for this thing.

[bohmankid]

1) There's a ton of motor mounts you can use. I personally used the adjustable Dirty Dingo mounts. They clear the crossmemeber but they're kind of expensive and won't allow you to use the AC in the lower stock location. I plan on moving my compressor to the top of the motor. The stock manifolds will most likely require the frame to be trimmed. Trailblazer SS manifolds are supposed to fit without issues.
2) if you're lowering the truck, you might want to look into putting a ls1 pan on the motor. The car oil pans are not as tall.
3) there are a bunch of places to send your harness or buy a new one. Hopefully someone else can chime in because I did my own. I sent my PCM to brenden at lt1swap.com to get codes deleted.
4) if you do your own harness, you also need the VATS deleted off your PCM before you can even start the truck.
5) I don't think you'll have issues running straight manifolds. Just don't drive too far and make sure the exhaust won't burn anything. It'll probly run like poo.

Good luck.
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[BR3W CITY]

Originally Posted by bloodybigblock

1. What motor mounts? I'd like to run the stock manifolds and i want to keep my a/c.
if you use ls adapter plates, you will use regular SBC mounts, as you would if your truck came with small block. As stated, stock truck manifolds will only clear on 1 side, TBSS manifolds or doug thorley swap headers are the most popular options

2. I plan on lowering the truck, will my truck pan cause issues? Is there motor mounts that can raise the engine?
The stock truck pan will usually hang up to an inch over the crossmember, you can try the car pans, or the GM "hot rod" aka LH8 pan

3. Best place to send my harness and ecm?
for my swap, I went with a complete new harness from fuelinjectionconnection it made wiring about a 25 minute job, included mounting everything. I did not send my ecm out, instead having it tuned by a local tuner.

4. If i do my own harness, can it be driven to get the tune an hour from my house?
VATS will stop that from happening. You have 3 choices. Send the ecm out and have vats and emissions removed OR have it towed to tuner OR pay the tuner some extra cash to come to your house....its not an option for everyone, but some guys might be willing to. My tuner was.

5. Any issues with running strait manifolds to make it to the muffler shop?
You won't have 02's in place, and it will run like trash. I would avoid doing so unless its real close or you don't have another option.


thats all the questions i have for now. Any help would be appreciated. Im ready to start buying parts for this thing.

in red

[Clyde65]

What he said! ^^^^^^^^^^^^^^^

[mrhurt73]

for TBSS manifolds refer to this thread. http://67-72chevytrucks.com/vboard/s...d.php?t=530623 i used them and they fit great, $120.00 delivered to my house.

i am betting you will like the f-body pan, i am going to have to use the caddy pan, but my crossmember is not factory. this thread has a bunch of part no for oil pans, http://67-72chevytrucks.com/vboard/s...d.php?t=558494

on the air conditioner, i wanted to use the 5.3L compressor so got one of these blocks, http://www.nostalgicairparts.com/air...ght-out-36.php
since Doc's Blocks is no longer in business, i found these guys.

[bloodybigblock]

Originally Posted by bohmankid

1) There's a ton of motor mounts you can use. I personally used the adjustable Dirty Dingo mounts. They clear the crossmemeber but they're kind of expensive and won't allow you to use the AC in the lower stock location. I plan on moving my compressor to the top of the motor. The stock manifolds will most likely require the frame to be trimmed. Trailblazer SS manifolds are supposed to fit without issues.
2) if you're lowering the truck, you might want to look into putting a ls1 pan on the motor. The car oil pans are not as tall.
3) there are a bunch of places to send your harness or buy a new one. Hopefully someone else can chime in because I did my own. I sent my PCM to brenden at lt1swap.com to get codes deleted.
4) if you do your own harness, you also need the VATS deleted off your PCM before you can even start the truck.
5) I don't think you'll have issues running straight manifolds. Just don't drive too far and make sure the exhaust won't burn anything. It'll probly run like poo.

Good luck.
Posted via Mobile Device

Is there a bracket that moved the a/c compressor that is somewhat cheap? I have seen a/c compressors in the stock location on our style trucks. I also do not mind trimming the frame for the 5.3 manifolds. Im sure a 3/4 ton frame can handle a small notch especially since the weight between a 454 and 5.3 will take some pressure off.

[bloodybigblock]

Originally Posted by BR3W CITY

in red

are the oxy sensors not in the stock manifolds? Any suggestion on how im suppose to have my exhaust done or a way i can drive it to the muffler shop? I was under the impression that if it was tuned, thatd you could drive it with strait manifolds/headers? Any comment on how i can keep my A/c? Thanks man

[Clyde65]

high mount compressor bracket here ( http://kwikperf.com/) you will also need a sanden compressor.

[bloodybigblock]

okay well imma have to find a style motor mount or adapters that work with the a/c mount in original spot. I cant see paying that to get a/c. Im sure there is a better way. Im definitely on a budget lol. Im sure someone will chime in on what mounts will work for me. Keeping my a/c and not spending a ton of money is in my way from buying what i need.

[Clyde65]

Give Clinebarger a message, he has a suburban ( 80's) that he put a 5.3 in a while ago, I bet he can help you a bunch.

[BR3W CITY]

Originally Posted by bloodybigblock

are the oxy sensors not in the stock manifolds? Any suggestion on how im suppose to have my exhaust done or a way i can drive it to the muffler shop? I was under the impression that if it was tuned, thatd you could drive it with strait manifolds/headers? Any comment on how i can keep my A/c? Thanks man

Nope, the front 02's are mounted in what would be referred to as the down pipe or B pipe. Unfortunately....my solution for this was like bringing a sledgehammer to a walnut cracking festival.....I went a bought a MIG.

The easiest option is to call your exhaust shop or a junkyard and see if you can get that pipe off a donor vehicle. You will need the flanges and a stub up pipe approxomately 6-10" long, it will contain o2 bungs. If you cannot find a stock one, you can buy (sometimes) or fab (what I had to do) a set of flanges and an exhaust stub, then weld the bungs in place.

[bloodybigblock]

haha, well you did work. So HELL YEAH! i can just get the B pipe past where the 0xy2 sensor is. Thatll work right? The a/c is what sucks, im about to say piss on it, i have 4 huge windows that roll down haha

thanks for your help also clyde

[BR3W CITY]

Yes, if you can get one it will work just fine. You can always fab another or modify it. Were I to do it again, I'd consider going with stainless, but for cost it really hasn't seemed worth it.

[Hart_Rod]

There's a lot of great info here!

[shortbed70]

Useful info as I hope to be gathering parts this spring!!!
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[High ho silverado]

If u go to the lsx swap faq u can find tons of info, and parts lists that some guys have put together. As far as 2wd headers for under 300 schoenfeld has a set of long tubes that work really good, I used them on my 4wd and they worked as well and they have o2 bungs already in them. Holly has a sweet r4 compressed mount that mounts the compressor up high and u can use the 90-91 blazer factory hoses, the bracket is around 130 bucks and is aluminum like the other ls brackets the only catch is u have to buy a spacer kit if ur using truck accesories and its a little over a hundred by its self but looking at it u can make ur own spacers and save a little money. As far as using the factory ac go to glocks build and it lays it out pretty well on the best way to do it.
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[mrhurt73]

here is the stub pipe cut off the donor truck that i am using. i have the TBSS manifolds and going to put these on and add to it with a little help from buddy with tubing bender.

[BR3W CITY]

good deal, using those means you can use the stock style gaskets as well.

[iceship]

Did you have to shorten driveshaft..